Heat exchanger for furnace pipes and the like

ABSTRACT

A heat exchanger device for use between a furnace or boiler and chimney comprising a housing pipe and heat transfer thin metal disks with vanes arranged spoke like. Each disk has an annulus in tight contact with the interior of the pipe and the vanes, being thin and confined between a center hub-like structure and the annulus, tend to warp to increase their angular deflection of the gasses as the temperature rises to effect pronounced scouring on the interior of the pipe to maximize heat transfer into the pipe and thereby to the atmosphere. The annuli of the axially spaced disks are rigidified by interconnecting rods.

United States atet 1 1 1111 3,736,961

Walsh 1451 June 5, 1973 [54] HEAT EXCHANGER FOR FURNACE 2,185,484 1 1940Welch et a1 ..165/154 x PIPES AND THE LIKE [76] Inventor: Robert D.Walsh, 11 s. 544 Oak- P Exam'fi1echarles, Myhre wood Avenue, Lemont, L60439 Asszstant ExammerS.J. R1chter Attorney-John J. Kowalik [22] Filed:Nov. 10, 1971 [21] App1.No.: 197,228 ABSTRACT A heat exchanger devicefor use between a furnace or 52 us. C1 ..138/38, 110 97 D, 165/40,boiler and chimney comprising a housing P p and 165/179 heat transferthin metal disks with vanes arranged [51] Int. Cl. ..FlSd 1/02, F28f1/40 spoke like. E h i k has an annulus in tight contact [58] Field ofSearch ..138/38; 165/40, 154, with the interior of the p p and thevanes, being thin [56] References Cited UNITED STATES PATENTS 2,879,9763/1959 Rose ..165/154 X 1,880,533 10/1932 Thomas ..165/154 2,268,38612/1941 Fisher ...165/156 X 2,890,866 6/1959 Hansen ..165/154 X andconfined between a center hub-like structure and the annulus, tend towarp to increase their angular deflection of the gasses as thetemperature rises to effect pronounced scouring on the interior of thepipe to maximize heat transfer into the pipe and thereby to theatmosphere. The annuli of the axially spaced disks are rigiditied byinterconnecting rods.

7 Claims, 9 Drawing Figures Patented June 5, 1973 3,736,61

2 Sheets-Sheet. 1

Inventor FIG 4 Robert D. Walsh Attorney Patented June 5, 1973 3,736,351

2 Sheets-Sheet 2 FIG] FIGS H69 HEAT EXCHANGER FOR FURNACE PIPES AND THELIKE DISCUSSION OF THE PRIOR ART Insofar as is known by the inventor,heat exchangers of the type under consideration have either constrictedthe flow of gasses of combustion into the chimney or permitted excessiveflow so that most of the heat is exhausted into the chimney.Furthermore, the more effective units are relatively expensive to makeand incorporate complex controls to vary the air flow.

SUMMARY OF THE INVENTION The primary object of the invention is toprovide a novel, effective heat exchanger which is relatively simple andinexpensive to make and which is easy to clean and service.

A further object is to provide a heat exchanger which incorporates diskswith thin gas-flow controlling blades which are adapted to warp as thetemperature rises to obtain a swirling effect in the chamber so as todissipate the heat into the housing and thereby into the atmosphere.

The invention comprehends a structure in which the heat transfer disksare adapted to be added or removed as requirements dictate.

A further object is to provide a novel device of the class described inwhich the vaned disks are notched about their peripheries and receiveflexible longitudinal positioning rods therethrough, the rods adapted tobe skewed in the annular pipe in order to offset the disks and also totighten the assembly by twisting the rods whereby they assume ahelicoidal shape in the pipe and hold the parts in tight engagement witheach other and in good heat transfer relation.

These and other objects and advantages inherent in and encompassed bythe inventions will become more readily apparent in the specificationand the drawings, wherein:

FIG. 1- is a perspective view showing the invention applied between aboiler or furnace and a chimney;

FIG. 2 is an axial sectional view of the heat exchanger;

FIG. 3 is a crossectional view on a reduced scale taken substantially online 33 of FIG. 2;

FIG. 4 is a fragmentary perspective view of the heat exchanger assembly;

FIG. 5 is an enlarged cross-sectional view taken substantially on line5-5 of FIG. 4;

FIG. 6 is a cross-section on line 6-6 of FIG. 4;

FIG. 7 is a cross-section of a further embodiment of the invention;

FIG. 8 is a sectional view on an enlarged scale taken substantially online 8-8 of FIG. 7, and

FIG. 9 is an axial section taken on line 99 of FIG. 8.

DESCRIPTION OF FIGS. 1 6.

The heat exchanger generally designated 2 is fitted between the exhaustof the boiler or furnace 3 and the flue opening 4 of the chimney 5.

The exchanger comprises a preferably galvanized steel pipe 6 of hollowcylindrical form and reduced inlet and outlet end portions 7 and 8. Atleast the outlet end portion has an annular tubular portion 9 fittedwithin the adjacent end 10 of the pipe 6 and the portion 9 is connectedto pipe 6 by self-tapping screws 11. A

frusto-conical section 12 connects the ring 9 with the reduced pipeextension 13. Similarly the inlet end is formedwith a frusto-conicalportion 14 and a reduced end pipe 15. Thus the heat exchanger is largerin diameter than the inlet or outlet. This provides an expansion chamberand the constricted outlet to trap and efficiently transfer the heatfrom the chamber 16 to the pipe wall 6 and thereby transfer byconvection and otherwise the heat into the surrounding atmosphere.

The interior surface 19 of the pipe 6 is cylindrical and in intimatecontact with the edges 20 of annular heat transfer elements 21 which notonly serve to transfer heat to the pipe by conduction but also serve toswirl the heat entrained air within the transfer chamber.

Each element 21 is a thin disk of sheet metal such as galvanized steelalthough other metals may be used, and comprises a peripheral annulus orring 23 which is a relatively narrow band connected by radiallyextending vanes 24, 24 formed in the manner of spokes and connected to acentral hub-like support 25. The vanes are connected by reversely bentend connectors 26, 27 (FIG. 6) to the support 25 and the annulus 23 andthe vanes of each disk are offset circumferentially of the vanes of theadjacent disks so as to cause the gasses flowing from the inlet to theoutlet to swirl within the chamber and thus bathe the vanes and theinterior of the pipe with the hot gasses so as to extract maximum heattherefrom. As the temperature rises the vanes tend to expand and beingconfined tend to warp and twist so as to distort the angle of incidenceof each blade with the path of gas flow, and thus create a deviate paththrough the chamber thus increasing the dwell of the gasses within thechamber. The distortion of the blades is accommodated by the offsetconstruction of the end connectors 26, 27 which are of thinner sectionthan the blades and the center support and annulus since these portionsmust be stretched in the upsetting. They also are bendable transverselydifferent amounts along the width of the blade since they are ofgenerally triangular shape.

The outer edge 20 of each annulus is notched at 31, 31 and connectorrods or bars 32, 32 are fitted therein. These bars are thin incross-section and are flexible and have their outer sides 33 slidablyfitted against the interior surface of the housing. After the diskassembly is fitted into the chamber, the assembly may be twisted so thata tight fit develops since the bars tend to be twisted, it beingunderstood that the notches 31 are dimensioned to accommodate suchslight twisting. The twisting may be preceded by spraying the surface 19with a light evaporative lubricant prior to insertion of the diskassembly.

EMBODIMENT OF FIGS. 7-9.

In the present embodiment parts identical with the previous embodimentare identified with the same reference numerals.

The housing 6 encases the heat-transfer finned radiator or diverter 50which is similar to heat transfer element 21 of the previous embodiment,and comprises for simplicity of manufacture, a center rod 51 which hasthreaded ends 52, 53 on which are threaded nuts 54,54. A stack or spacerspools 55,55 and intervening finned or vaned metal disks 56,56 aresleeved on the shaft 51. Each disk 56 has an annular peripherical por:tion or outer ring 57 with its outer periphery 58 in intimate contactwith the interior surface 19 of the center section 6. Each disk hasangled, circumferentially spaced, radial blades or vanes 59 which extendbetween the inner and outer rings 57,60 and are formed with these assheet metal stampings in a single piece. The thinness of the vanescombined with the angularity of the blades and close confinement of thedisks are conducive to the blades warping and thus producing anonuniform labyrinthian passageway 65 between the blades and through theintervening spaces between the disks for the hot gasses passing from theinlet to the outlet, particularly when adjacent disks are arranged withtheir vanes offset from each other. It will be seen that each inner ringhas a center aperture 69 receiving the rod therethrough and the disksare held tightly on the rod by the end nuts.

Several embodiments of the invention have been described, however otherforms will now become readily apparent and would come within the scopeof the appended claims.

I claim: 4

1. For use between a boiler and the like and a chimney, a heat exchangerfor conducting hot combustion gasses therethrough comprising anelongated housing providing a chamber having an inlet and an outletmeans and diverter means within the chamber for circulating such gasseswithin said chamber, said diverter means being formed of heat conductingmaterial, self regulating means mounting said diverter means within saidchamber for adjusting the positions thereof within said chamber, saiddiverter means comprising a plurality of disks with vanes thereon, andsaid means mount- 4 ing said disks within said chamber comprisingflexible connecting bars adapted to be shifted within the chamberaxially and circumferentially thereof for skewing said diverter means.

2. The invention according to claim 1 and said housing and divertermeans being made of metal for conducting heat from within the chamber tothe surrounding atmosphere and said diverter means comprising thindiskshaving radial vanes, a peripheral annulus, and a center support andmeans connecting the ends of the vanes to said annulus and support andhaving a modulus of expansion and contraction different than said vanes.

3. The invention according to claim 2 and said connecting meanscomprising integral flanges on the ends of said vanes and of thinnersection than the vanes.

4. The invention according to claim 3 and said flanges tapering midwiseof said vanes.

5. The invention according to claim 4 and said skewing means comprisingflexible bars interposed between the interior of the housing and thedisks and adjustably interlocked with the latter and displaceableaxially within the chamber.

6. The invention according to claim 1 and said vanes having flangesconnecting them with the adjacent portions of the disks and theflangesbeing of different section than the vanes.

7. The invention according to claim 6 and said housing having reducedinlet and outlet ends and said disks having intimate peripheral contactwith the housing.

1. For use between a boiler and the like and a chimney, a heat exchangerfor conducting hot combustion gasses therethrough comprising anelongated housing providing a chamber having an inlet and an outletmeans and diverter means within the chamber for circulating such gasseswithin said chamber, said diverter means being formed of heat conductingmaterial, self regulating means mounting said diverter means within saidchamber for adjusting the positions thereof within said chamber, saiddiverter means comprising a plurality of disks with vanes thereon, andsaid means mounting said disks within said chamber comprising flexibleconnecting bars adapted to be shifted within the chamber axially andcircumferentially thereof for skewing said diverter means.
 2. Theinvention according to claim 1 and said housing and diverter means beingmade of metal for conducting heat from within the chamber to thesurrounding atmosphere and said diverter means comprising thin diskshaving radial vanes, a peripheral annulus, and a center support andmeans connecting the ends of the vanes to said annulus and support andhaving a modulus of expansion and contraction different than said vanes.3. The invention according to claim 2 and said connecting meanscomprising integral flanges on the ends of said vanes and of thinnersection than the vanes.
 4. The invention according to claim 3 and saidflanges tapering midwise of said vanes.
 5. The invention according toclaim 4 and said skewing means comprising flexible bars interposedbetween the interior of the housing and the disks and adjustablyinterlocked with the latter and displaceable axially within the chamber.6. The invention according to claim 1 and said vanes having flangesconnecting them with the adjacent portions of the disks and the flangesbeing of different section than the vanes.
 7. The invention according toclaim 6 and said housing having reduced inlet and outlet ends and saiddisks having intimate peripheral contact with the housing.